The joint capsules of our body are an important component for all movements. They are made of connective tissue and surround all our joints. Inside it is the joint cavity, which is filled with synovial fluid. Joint capsules are mainly responsible for the stability and lubrication of joints.
What is a joint capsule?
Every joint in our body also has a joint capsule. In technical circles, the joint capsule is called the capsula articularis. This completely encloses the joint cavity, which is filled with synovial fluid. This fluid is important for the smooth movement of our joints because it lubricates the moving parts of the joints. The joint capsule thus provides protection for our joints and ensures the existing stability of all joints. Thus, when injuries occur, the joint capsule is always affected first, before damage occurs to the actual joint. The joint capsule also seals the respective joint so that the joint fluid does not leak out.
Anatomy and structure
The joint capsules in our body consist of two layers: Membrana fibrosum and Membrana synoviale (synovial membrane). Membrana fibrosum is mainly responsible for the mechanical strength and movement possibilities of the joints. It therefore determines the possible directions of movement. It stabilizes the joint and guides it in the movements. It consists mainly of collagenous connective tissue. At the joint edge it is fused with the periosteum. The membrana fibrosum also communicates the current position of the joint to the brain and controls the movements. The membrana synoviale, on the other hand, has a very loose structure and is located within the membrana fibrosum. Its main function is to break down the abrasion products that result from normal movements. It contains many nerve fibers and receptors, which results in a high pain sensitivity of the membrana synoviale. It is also responsible for the regulation of joint fluid (synovial fluid). When needed, this is produced or also broken down. The joint capsules in the body are the central trigger for pain in the joints and therefore also responsible for movement restrictions.
Function and tasks
The main task of the joint capsules in our body is to enable movement. The special structure of our joints makes the interaction of movements and control by the brain possible in the first place. Without joint capsules, controlled movement would therefore not be possible at all. The joint capsules determine the possible directions of movement. This is why the joints in healthy people can only be moved or rotated in certain predetermined directions. The joint capsule also has the main task of protecting the joint. It completely encloses the joint as a protective mantle. Without the joint capsule, our joints would also have significantly less stability. The production and regulation of synovial fluid in the joint capsules is also responsible for smooth movements. Without the synovial fluid, our joints would be much more difficult to move and would also show signs of wear much more quickly. The sensation of pain is also controlled by the joint capsule. The articular cartilage, on the other hand, cannot feel pain. If the joint is damaged, the information to the brain always comes from the joint capsule. It then signals pain to the brain, which subsequently causes movement restrictions to minimize the risk of further damage.
Diseases and complaints
Our joint capsules can cause problems due to aging, diseases or accidents. Very well known in this context are osteoarthritis and arthritis. Osteoarthritis is a sign of wear and tear, but it goes beyond the usual, age-related level. The cause of this unnatural wear and tear may be excessive stress over a long period of time, or it may be caused by accidents. Congenital causes can also trigger arthritis. Arthritis, on the other hand, is a widespread inflammation of the joints. Here there are bacterially caused inflammations, or those that have rheumatic causes. The joint may swell and redness may occur. Often a joint effusion is also formed. The diagnosis of capsular rupture also occurs time and again, mainly in athletes.If a sudden and rapid movement is made during sports, the joint can be stressed beyond its normal radius and the result can be a capsular tear. This is damage to the connective tissue at the joint capsule. A capsular tear can be recognized by swelling, pulsating pain and there may also be a bruise. The swelling occurs because the joint fluid leaks through the tear in the joint capsule. This also causes the restriction of movement. A capsular tear can also be caused by the uncontrolled impact of a ball or by twisting the respective joint.
